Alpha diversity of Salticidae (Arachnida: Araneae) in a tropical dry forest in south Morelos, Mexico

Abstract

Spiders are the seventh more diverse order among arthropods with 44,540 described species in the world; inside this order, the family with the greatest number of species is Salticidae, with near 5,678 species. For Mexico there have been reported 59 genera and 242 species, although the diversity of this family is still poorly known. In an effort to increase the knowledge of this family in the country, this work has the purpose to generate an inventory of species and to analyze the diversity of Salticidae in three localities of a tropical dry forest in south Morelos: San Miguel de los Elotes and Huautla-Ajuchitlan, both in the municipality of Tlaquiltenango and El Limón de Cuauchichinola, in the municipality of Tepalcingo. Two of these localities (“El Limon” and “Huautla-Ajuchitlan”) belong to the Biosphere Reserve Sierra de Huautla. Samples were collected monthly from April-2013 to March-2014 for each locality, using the technique of vegetation beat with an entomological umbrella along a variable length transect. For the diversity analysis the concept of true diversity according to Jost (2006) is used. A total of 166 adult individuals were collected in 61 morphospecies; from this, 82 individuals in 35 morphospecies are from San Miguel de los Elotes, 59 individuals in 37 morphospecies from Huautla-Ajuchitlan and 25 individuals in 17 morphospecies from El Limón de Cuauchichinola. The more abundant genera were Sassacus and Thiodina with 40 and 24 individuals, respectively. In the other hand Lyssomanes only have one individual. The true alpha diversity for San Miguel de los Elotes was 22.18 effective number of species, for Huautla-Ajuchitlan was 31.79 and for El Limon de Cuauchichinola was 14.21, showing that Huautla-Ajuchitlán is the richest locality, probably due to its microclimatic conditions. In contrast the locality showing more abundance of individuals was San Miguel de los Elotes, which is the most perturbed too. For the beta diversity, or replacement rate, the three communities were compared in paired and the results were as follows: for San Miguel de los Elotes vs Huautla-Ajuchitlán was 1.5, from Huautla-Ajuchitlán vs El Limon de Cuauchichinola was 1.4 and for El Limon de Cuauchihinola vs San Miguel de los Elotes was 1.4, showing that the species composition is very similar, although these are preliminary results. This has become the first study in Morelos and the fourth research in Mexico studying the fauna of Salticidae at a local scale, showing the need of more local work in Mexico with groups like this.